This invention pertains to refractory composition. More particularly, the present invention relates to a refractory composition suitable for gunning, ramming or casting a monolithic structure.
When refractory mixes, particularly those for gunning, were first developed, the practice was to use conventional refractory bonds such as sodium silicate or magnesium sulfate, as the bonding agent. While useful for their intended purpose, these mixes did not always exhibit maximum performance characteristics. For instance, if these mixes containing conventional bonding systems are used for gunning, there may arise some shortcomings since gunning mixes must mix readily with water, adhere well to a furnace wall without slumping or rebounding and must set to a coherent mass very rapidly. If these mixes containing conventional bonding systems are used for casting or ramming, they also may function well but increased performance is always desirable.
Accordingly, special bonding systems have been developed.
U.S. Pat. No. 3,357,842 discloses a bonding system using monosodium phosphate.
U.S. Pat. No. 3,357,843 discloses a bonding system using glassy polyphosphates, particularly sodium tripolyphosphate.
U.S. Pat. No. 3,879,208 discloses a bonding system using aluminum sulfate.
U.S. Pat. No. 4,463,100 discloses a refractory composition containing a stabilized lime aggregate wherein dicalcium silicate is the major crystalline phase in the aggregate.
U.S. Pat. No. 2,619,426 discloses a refractory composition suitable for ramming, casting, or pressing, or for use as a mortar, and bonded with a combination of aluminum sulfate and calcium phosphate.
U.S. Pat. No. 4,276,901 discloses a refractory composition containing from 0.5 to 5% bentonite; from 1.5 to 10% of a bonding system consisting of from 1 to 5% alkali metal phosphates and from 0.5 to 5% aluminum sulfate; and up to 10% pitch.
U.S. Pat. No. 3,490,930 discloses a refractory composition consisting of refractory grain selected from the group consisting of magnesia, chromite, and admixtures of magnesia and chromite with each other; a bonding agent consisting of 1% to 5% of a hydrated alkali metal borate; and a plasticizer consisting of 1% to 5% of a plastic swelling clay.